This invention relates to apparatus for controlling the rotational fluctuation of supply rolls. In particular, this invention relates to an apparatus for suppressing high frequency rotational fluctuations which are generated when unrolling the supply rolls of web materials having an adhesive applied thereto such as adhesive tapes, films and the like.
The web materials having an adhesive applied on at least one surface thereof such as adhesive tapes or films are generally wound up into rolls for ease of handling and storage. These rolls are called "the supply roll". In order to use or consume the adhesive tape, it must be stripped away from the supply roll. In industrial applications, the stripping of the adhesive tape from the supply roll is automatically carried out by various unrolling machines. Although the unrolling operation of the adhesive tape roll by the conventional machines is efficient and generally satisfactory, some operational problems remain to be solved. One of the most important of these, for example, is that the rotation of the supply roll fluctuates peripherally at relatively high frequencies while the adhesive tape is being stripped away from the roll by an unwinding force at a substantially fixed speed. The high frequency peripheral or rotational fluctuation of the supply roll while being rotated by the unrolling force is believed to be caused primarily due to the fact that the peel off resistance against the unrolling of the tape which is produced by the adhesion between the tape surfaces in the roll changes during the unrolling operation. Further, once a cycle of such peripheral or rotational fluctuation is initiated it tends to continue through the entire operation. If the supply roll fluctuates in the peripheral direction at a relatively high frequency during rotation, then the length of the adhesive tape being stripped away goes through a vigorous flapping with the tension applied thereto widely changing. At the same time, objectionable flapping and peel-off noises are generated. For a smooth and acceptable unrolling of the supply roll, in particular of the adhesive web materials, it is highly desired to eliminate the high frequency rotational fluctuations of the supply roll.